An ultra-high molecular weight polyethylene (UHMW-PE) fiber is a synthetic fiber. Its molecular structure has very high straightening parallelism and degree of orientation, and such molecular structure determines that the ultra-high molecular weight polyethylene fiber has very high strength and modulus and has the advantages of good chemical stability, corrosion resistance and the like. The above properties of the ultra-high molecular weight polyethylene fiber are better than those of an aramid fiber, and the ultra-high molecular weight polyethylene fiber is widely used in the field of bulletproof protection for military and polices and becomes a mainstream material replacing a traditional steel structure bulletproof material in the field.
The strength of a uni-directional cloth (Uni-Directional Cloth, also known as UD fabric) is centralized in a certain direction. A laid fabric can be prepared by crisscross laminating the multiple uni-directional cloth at certain angles. At present, the laid fabric made of the ultra-high molecular weight polyethylene fibers is generally prepared by adopting the following process: tidily arranging multiple ultra-high molecular weight polyethylene fibers by a warping process of realizing uniformity, parallelism, straightness and the like, bonding the various fibers with an adhesive to prepare the uni-directional cloths, sequentially crisscross spreading the multiple uni-directional cloths according to 0 degree/90 degrees and bonding the uni-directional cloths with the adhesive to prepare the laid fabric.
The uni-directional cloth prepared by the existing process comprises: the multiple ultra-high molecular weight polyethylene fibers which are warped along a direction and bonded into a whole. As each ultra-high molecular weight polyethylene fiber is of a tow-like structure and each ultra-high molecular weight polyethylene fiber is an independent individual, the warping process of the fibers is complex, the production cost is high, the fibers are liable to breaking, distortion, intertwining, knotting, non-uniform arrangement and other defects in warping, coating and other process flows, these defects will hinder the effective energy transfer of external force by the uni-directional cloth or the laid fabric and are liable to causing stress concentration, and the strength, the bulletproof performance and other performances of the uni-directional cloth or the laid fabric are further reduced.